Search results for "kuulo"
showing 10 items of 90 documents
MEG induced activation measures in describing auditory cortex maturation
2015
Kuuloaivokuoren ärsykkeisiin liittyvien neuraalisten oskillaatioiden kehitystä ihmisellä ei vielä täysin tunneta. Tämän tutkimuksen tavoitteena on kuvata auditorisen prosessoinnin kehitystä induced-aktivaation ja phase-locking-arvon avulla. Koehenkilöt olivat 6–13,5-vuotiailta lapsia (N=36) sekä aikuisia (N=11). Koko pään kattavaa magnetoenkefalografiaa (MEG) käytettiin nauhoittamaan aivokuoren aktivaatiota passiivisen kuuntelun tehtävän aikana. Osallistujille esitettiin yksinkertaisia siniääniä (1000 Hz, kesto 50 ms) ärsykkeenä erikseen molempiin korviin. Induced-aktivaatiosta ja phase-locking-arvosta laskettiin aika-taajuuskuvat (time-frequency representation) sekä vasemman että oikean he…
Auditory duration discrimination in children with reading disorder, attention deficit or both
2009
Tiina Huttunen-Scott tutki väitöskirjassaan kuulonvaraisen keston erottelun ongelmien esiintymistä lapsilla, joilla on vaikeuksia joko lukemisessa, tarkkaavaisuudessa tai molemmissa. Kuullun erottelun ongelmat voivat vaikuttaa puheäänteiden hahmottamiseen ja prosessointiin ja johtaa vaikeuksiin lukemaan oppimisessa.Huttunen-Scott havaitsi kuullun keston erottelun olevan merkitsevästi heikentynyt lapsilla, joilla on lukemisvaikeuksia. Erottelu oli heikentynyt jopa laajemmin lapsilla, joilla on lukemisvaikeuksien ohella myös tarkkaavaisuuden ongelmia. Sen sijaan lapsilla, joilla on vain tarkkaavaisuuden ongelmia, erottelu ei ollut heikentynyt, mikä viittaa siihen, että kuulonvaraisen prosesso…
Hearing in Real-Life Environments (HERE) : Structure and Reliability of a Questionnaire on Perceived Hearing for Older Adults
2019
Supplemental Digital Content is available in the text.
Change detection to tone pairs during the first year of life – Predictive longitudinal relationships for EEG-based source and time-frequency measures
2019
Abstract Brain responses related to auditory processing show large changes throughout infancy and childhood with some evidence that the two hemispheres might mature at different rates. Differing rates of hemispheric maturation could be linked to the proposed functional specialization of the hemispheres in which the left auditory cortex engages in analysis of precise timing information whereas the right auditory cortex focuses on analysis of sound frequency. Here the auditory change detection process for rapidly presented tone-pairs was examined in a longitudinal sample of infants at the age of 6 and 12 months using EEG. The ERP response related to change detection of a frequency contrast, i…
Memory-Based Mismatch Response to Frequency Changes in Rats
2011
Any occasional changes in the acoustic environment are of potential importance for survival. In humans, the preattentive detection of such changes generates the mismatch negativity (MMN) component of event-related brain potentials. MMN is elicited to rare changes (‘deviants’) in a series of otherwise regularly repeating stimuli (‘standards’). Deviant stimuli are detected on the basis of a neural comparison process between the input from the current stimulus and the sensory memory trace of the standard stimuli. It is, however, unclear to what extent animals show a similar comparison process in response to auditory changes. To resolve this issue, epidural potentials were recorded above the pr…
Human brain ages with hierarchy-selective attenuation of prediction errors
2020
Abstract From the perspective of predictive coding, our brain embodies a hierarchical generative model to realize perception, which proactively predicts the statistical structure of sensory inputs. How are these predictive processes modified as we age? Recent research suggested that aging leads to decreased weighting of sensory inputs and increased reliance on predictions. Here we investigated whether this age-related shift from sensorium to predictions occurs at all levels of hierarchical message passing. We recorded the electroencephalography responses with an auditory local–global paradigm in a cohort of 108 healthy participants from 3 groups: seniors, adults, and adolescents. The detect…
Children show hemispheric differences in the basic auditory response properties
2019
Auditory cortex in each hemisphere shows preference to sounds from the opposite hemifield in the auditory space. Besides this contralateral dominance, the auditory cortex shows functional and structural lateralization, presumably influencing the features of subsequent auditory processing. Children have been shown to differ from adults in the hemispheric balance of activation in higher-order auditory based tasks. We studied, first, whether the contralateral dominance can be detected in 7- to 8-year-old children and, second, whether the response properties of auditory cortex in children differ between hemispheres. Magnetoencephalography (MEG) responses to simple tones revealed adult-like cont…
Hearing and Quality of Life Among Community-Dwelling Older Adults
2018
Objectives Hearing loss is a common health concern in older people, and the prevalence of hearing loss increases with aging. Poor hearing may cause difficulties in everyday life situations and reduce quality of life (QoL). The aim of this study was to assess the associations between different domains of QoL (physical, psychological, social, and environmental), perceived hearing difficulties in various everyday situations, and audiometrically measured hearing level among community-dwelling older adults. Method Cross-sectional analysis of 76- to 91-year-old community-dwelling adults. Data on QoL (WHO Quality of Life Assessment short version) and perceived hearing difficulties were gathered vi…
Electrophysiological evidence of memory-based detection of auditory regularity violations in anesthetized mice
2017
In humans, automatic change detection is reflected by an electrical brain response called mismatch negativity (MMN). Mismatch response is also elicited in mice, but it is unclear to what extent it is functionally similar to human MMN. We investigated this possible similarity by recording local field potentials from the auditory cortex of anesthetized mice. First, we tested whether the response to stimulus changes reflected the detection of regularity violations or adaptation to standard stimuli. Responses obtained from an oddball condition, where occasional changes in frequency were presented amongst of a standard sound, were compared to responses obtained from a control condition, where no…
Context-dependent minimisation of prediction errors involves temporal-frontal activation
2020
According to the predictive coding model of perception, the brain constantly generates predictions of the upcoming sensory inputs. Perception is realised through a hierarchical generative model which aims at minimising the discrepancy between predictions and the incoming sensory inputs (i.e., prediction errors). Notably, prediction errors are weighted depending on precision of prior information. However, it remains unclear whether and how the brain monitors prior precision when minimising prediction errors in different contexts. The current study used magnetoencephalography (MEG) to address this question. We presented participants with repetition of two non-predicted probes embedded in cont…